The present invention relates to flexible barriers. These are normally erected on slopes to protect manufactured articles such as railways, roads, villages, etcetera, from the fall of boulders.
The walls of traditional crash barriers are made up of a series of vertical poles placed a few meters apart from each other; between these, metal sheet section irons are placed,, that sustain the impact of falling boulders. This type of barrier has been shown to be very expensive: in fact it has to be extremely strong in order to take up the thrust of the impact of a boulder.
Furthermore, after every collapse, one must take care to repair such a barrier.
Other crash barriers have been studied, so-called elastic barriers, which have between two rigid vertical poles, a flexible metallic net, or a series of steel cables, arranged horizontally with a distance between them of 0.2-0.3 m, which can better take up the thurst of the impact of the falling boulders.
This structure, even if cheaper and having a longer lifespan than the rigid one, still doesn't solve the problem of the poles; these are in fact subject to breakages caused by boulders falling directly on them.
The patent FR 1.190.613 envisages poles pivoted at the lower end, and a net anchored at points along its perimeter, so that it becomes subdivided in triangles fixed at their vertices, which act independently to one another, In this case, the energy dissipation due to the falling boulder must always occur in a very limited area, thus diminishing the total load that the structure can support.